Uses of low-molecular-weight heparin

The Effect of Heparin and Other Exogenous Glycosaminoglycans (GAGs) in Reducing IL-1β-Induced Pro-Inflammatory Cytokine IL-8 and IL-6 mRNA Expression and the Potential Role for Reducing Inflammation

Glycosaminoglycans (GAGs) are long linear polysaccharides found in every mammalian tissue. Previously thought only to be involved in cellular structure or hydration, GAGs are now known to be involved in cell signaling and protein modulation in cellular adhesion, growth, proliferation, and anti-coagulation. In this study, we showed that GAGs have an inhibitory effect on the IL-1β-stimulated mRNA expression of IL-6 and IL-8. Exogenous heparin (p < 0.0001), heparan (p < 0.0001), chondroitin (p < 0.049), dermatan (p < 0.0027), and hyaluronan (p < 0.0005) significantly reduced the IL-1β-induced IL-8 mRNA expression in HeLa cells. Exogenous heparin (p < 0.0001), heparan (p < 0.0001), and dermatan (p < 0.0027) also significantly reduced IL-1β-induced IL-6 mRNA expression in HeLa cells, but exogenous chondroitin and hyaluronan had no significant effect. The exogenous GAGs may reduce the transcription of these inflammatory cytokines through binding to TILRR, a co-receptor of IL-1R1, and block/reduce the interactions of TILRR with IL-1R1.

Macroscopic hematuria in patients on anticoagulation therapy

INTRODUCTION

Visible hematuria is not rare in patients on anticoagulant therapy. There is no consensus regarding the diagnostic approach for them; some authors suggest restricted volume of diagnostic procedures because of the low number of urological etiology found. Some antibiotics have been reported to potentiate the effect of oral anticoagulants.

MATERIAL AND METHODS

The study addresses the need for urological assessment of patients on anticoagulation therapy and the possible role of some drugs administrated simultaneously with an oral anticoagulant, for the onset of macroscopic hematuria. Patients hospitalized with hematuria, both with or without anticoagulation therapy, were investigated and followed up.

RESULTS

The onset of hematuria depends on the monitoring of oral anticoagulation. INR (International Normalized Ratio) value corresponds with the probability of non-urological etiology, where INR>4 carries relatively low risk for urological and malignant etiology. Some antibiotics may influence the anticoagulation effect, so INR value may be elevated and hematuria may occur.

CONCLUSIONS

Anticoagulation therapy should be administrated carefully and individually. The risk of urological etiology of hematuria is lower in patients on oral anticoagulants (especially when INR >4), however, it is not zero.

Low-molecular-weight heparin-conjugated liposomes with improved stability and hemocompatibility

Multilamellar vesicles (MLV) containing phosphatidyl choline (PC), cholesterol (CHOL), and stearylamine (SA) in the molar ratio of 7:2:0.2 were prepared by the thin film hydration method. Low-molecular-weight heparin (LMWH, MW: 3000) was conjugated with the MLV using carbodiimide (EDC). Infrared, Raman, and nuclear magnetic resonance spectra and DSC of each sample (MLV, LMWH, and MLV-LMWH) were obtained, enabling the authors to determine the chemical changes that occurred in the MLV structure at the end of the conjugation step. In addition, the changes in the chemical structures of the conjugated samples were revealed by the use of elemental analysis. Particle size analysis was used to determine the difference between the sizes of MLV and MLV-LMWH. In order to study the effect of LMWH on the behavior of MLV-LMWH in blood, osmotic fragility (in saline and plasma), hemolytic activity, and plasma recalcification time tests were carried out. These tests showed that it was possible to construct liposomes that would not induce reactions in the blood and would have potentially longer half-lives in the circulation.

Low-molecular-weight heparin for the prevention and treatment of venous thromboembolism in pregnancy

PURPOSE OF REVIEW

Low-molecular-weight heparins (LMWHs) have largely replaced unfractionated heparins for both prophylaxis and treatment of venous thromboembolism in nonpregnant patients. However, until recently, evidence in pregnant women was lacking, despite the increasing use of LMWHs during pregnancy in clinical practice. This review covers recent literature on the use of LMWHs in relation to pregnancy.

RECENT FINDINGS

The main areas covered in this review are the use of LMWHs in both prophylaxis and treatment of venous thromboembolism in pregnancy. The review also considers issues relating to monitoring of LMWHs in pregnancy, and safety from both a maternal and a fetal perspective.

SUMMARY

The available evidence demonstrates that LMWHs are of at least equivalent efficacy but have a better safety profile compared with unfractionated heparins in both prophylaxis and treatment of maternal venous thromboembolism, and are more convenient to administer. There is no consensus with respect to whether these agents require monitoring during pregnancy other than periodic checking of the platelet count. The clinical implication from the available evidence is that LMWHs should now be regarded as the anticoagulant agents of choice for both prophylaxis and treatment of maternal venous thromboembolism.

Effects of the glycoprotein IIb/IIIa receptor antagonist c7E3 Fab and anticoagulants on platelet aggregation and thrombin potential under high coagulant challenge in vitro

The present study was performed to investigate the combined effects of the platelet glycoprotein IIb/IIIa receptor antagonist c7E3 Fab (abciximab) and the anticoagulants unfractionated heparin (UH), low molecular weight heparin (LMWH), and recombinant hirudin (rH) on platelet aggregation and thrombin generation under high coagulant challenge by extrinsic activation of platelet-rich plasma. Platelet aggregation and thrombin generation were assessed simultaneously in the presence of different concentrations of abciximab and anticoagulants. Increasing concentrations of abciximab resulted in a dose-dependent anti-aggregating effect with a maximum at 20 microg/ml. Doses of 5, 10, and 20 microg/ml abciximab prolonged the lag phase until the onset of platelet aggregation, but this effect was independent of the dosage used. Abciximab had no influence on the thrombin potential under our high coagulant challenge. UH, LMWH, and rH showed a dose-dependent prolongation of the lag phase until the onset of platelet aggregation and decreased the thrombin potential. Addition of anticoagulants did not contribute to further inhibition of platelet aggregation in the presence of abciximab, but the combination of abciximab and anticoagulants exhibited an additive effect on prolongation of the lag phase until the onset of platelet aggregation. Addition of abciximab to anticoagulants did not result in further decrease of the thrombin potential. Our study demonstrates the respective specific effects of abciximab and anticoagulants on platelet aggregation and thrombin potential under high coagulant challenge, and also an additive effect of abciximab and the anticoagulants UH, LMWH, and rH on the lag phase until the onset of platelet aggregation.

Deep venous thrombosis: early discharge strategies and outpatient management

Conventional management of acute deep venous thrombosis (DVT) consists of initiating continuous infusion intravenous unfractionated heparin (UFH) for 5 days in the hospital as well as warfarin. Low-molecular-weight heparins (LMWHs) appear to confer similar protection against recurrent DVT compared with UFH but exhibit prolonged bioavailability; increased ease of dosing, and fewer side effects. The advent of LMWH has resulted in increased numbers of patients undergoing initial management of acute DVT with only several days of hospitalization. While 3-month follow-up studies with LMWH demonstrate similar efficacy and safety to UFH, longer term experience with these new agents is necessary to determine their optimal use and safety. We suggest a system for triage in the initial management of DVT patients for: (1) complete outpatient management with LMWH, or (2) short-term hospitalization for initiation of LMWH, or (3) 5-day hospitalization for treatment with UFH. A review of DVT management with LMWH and algorithms for each of these pathways are provided.

Low-molecular-weight heparin for venous thromboembolism

For prophylaxis and treatment of venous thromboembolism, low-molecular-weight heparin is as effective as standard, unfractionated heparin and has fewer adverse effects. Moreover, selected patients can use it at home.